This invention relates to an armchair or sofa structure transformable into a bed.
More particularly, the invention relates to a structure of the aforementioned type in which the seat structure is slidable longitudinally on a support base, and simultaneously with said sliding there open-apart two parts which form the back portion, namely a front part and rear part respectively, which on termination of their mutual withdrawal movement become disposed in the plane of the bed, as they are hinged together at their top.
Structures of this type are generally known, and they have enabled the problem of forming a structure transformable from a sofa or armchair into a bed and viceversa in an economically advantageous manner, without using the complicated and costly mechanisms of conventional sofa-bed frames.
However, such structures have drawbacks which make their use by the user difficult, and make the operations involved in transforming from one state of use to the other uncomfortable.
In this respect, it is known that said structures can be used only in two utilization positions, i.e. with the back portion completely vertical for use as a sofa or armchair, and with the back portion completely open for use as a bed respectively. It is not possible to set the structures in question in intermediate positions which can be likewise utilized by the user.
A further drawback of conventional structures is the fact that passage from the bed state to the sofa state is extremely laborious, particularly with regard to the initial operation involved in the upward folding movement, and the consequent mutual approach of the parts constituting the back portion.
A further drawback of currently known structures is that in order to maintain the structure securely in the sofa or armchair position, i.e. to prevent undesirable opening thereof, complex temporary locking members must be provided on the slidable part of the seat portion and on the fixed base, so that when in the closed position, said means prevent relative movements of these two parts.